1. Field of the Invention
The invention relates to a light source assembly, and in particular relates to a light source assembly using light emitting diodes (LEDs) as the light source.
2. Description of the Related Art
Liquid crystal displays (LCDs) are currently in wide use in a wide variety of information indicator displays. The main structure of an LCD includes a panel module and a backlight module. The panel module mainly include at lease a glass substrate, a liquid crystal layer, an alignment layer, a color filter, a polarizer, a driving IC, and others. The backlight module mainly include at least a light source, a light guide plate, a prism, a diffuser, a reflector sheet, and others. The backlight module provides light to the panel module for displaying information. The performance of an LCD is affected by all of the internal devices of which it is composed and the backlight module is primarily responsible for screen brightness, uniformity, contrast, and viewing angle.
Generally, the backlight module is classified as a side light type or a direct type according to the position of the light source. The side light type having the light source on the side edge of the panel module has a thinner backlight module and is suitable for portable LCD. The direct type having the light source under the panel module has good uniformity in brightness and has more space for light sources and is suitable for those displays requiring high brightness and wide viewing angle.
Due to the rapid advances in lighting efficiency, the LEDs are becoming more useful for LCDs. Technically speaking, it is hoped that, in the near future, the lighting efficiency of the LED can reach or exceed that of the cold cathode tube. Due to its swift response and feature of emitting visible light, such as red, blue and green, the LED has a great opportunity to play a leading role as the light source for use by the LCD industry.
The brightness of the LED provided to LCD depends not only on the LED itself but also on the design and assembly of the reflector sheet adjacent to the LED.
The covering area of the reflector sheet adjacent to the LED is closely related to the brightness of the LED.
Referring to FIG. 1A and FIG. 1B, in the related art, while using a plurality of LEDs 200 as light sources and considering the assembly tolerance of the reflector sheet 300 for some unexpected accounts that may cause the position of each LEDs 200 to change, the reflector sheet 300 needs a larger hole 350 and this will result in reducing the covering area of the reflector sheet 300. In other circumstances, the leads 250 of the LEDs 200 are electrically connected to the circuit board 100 by welding solder 400 to the circuit board 100 which causes the assembly surface to be uneven resulting in a bad interface with reflector sheet 300. The hole 350 of the reflector sheet 300 must be enlarged to avoid the welding position and this also will result in reducing the covering area of the reflector sheet 300.
Hence, a method of improving the covering area of the reflector sheet 300 so as to improve the lighting efficiency of the backlight module is desirable.